/*  $OpenBSD: wcsftime.c,v 1.3 2014/05/06 15:49:45 tedu Exp $ */
//#include "private.h"

/*
** Based on the UCB version with the ID appearing below.
** This is ANSIish only when "multibyte character == plain character".
**
** Copyright (c) 1989, 1993
** The Regents of the University of California.  All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. Neither the name of the University nor the names of its contributors
**    may be used to endorse or promote products derived from this software
**    without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
*/

#include "private.h"
#include "tzfile.h"
#include "fcntl.h"
#include "stdlib.h"
#include "wchar.h"

#ifdef LOSCFG_KERNEL_CPPSUPPORT
#include "los_cppsupport.h"
#endif

#ifndef INT_STRLEN_MAXIMUM
/*
** 302 / 1000 is log10(2.0) rounded up.
** Subtract one for the sign bit if the type is signed;
** add one for integer division truncation;
** add one more for a minus sign if the type is signed.
*/
#define INT_STRLEN_MAXIMUM(type) \
    ((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
    1 + TYPE_SIGNED(type))
#endif /* !defined INT_STRLEN_MAXIMUM */

#define TM_JANUARY  0
#define TM_DECEMBER 11


struct lc_time_T {
    const wchar_t * mon[MONSPERYEAR];
    const wchar_t * month[MONSPERYEAR];
    const wchar_t * wday[DAYSPERWEEK];
    const wchar_t * weekday[DAYSPERWEEK];
    const wchar_t * X_fmt;
    const wchar_t * x_fmt;
    const wchar_t * c_fmt;
    const wchar_t * am;
    const wchar_t * pm;
    const wchar_t * date_fmt;
};

#define Locale  (&C_time_locale)

static const struct lc_time_T   C_time_locale = {
    {
        L"Jan", L"Feb", L"Mar", L"Apr", L"May", L"Jun",
        L"Jul", L"Aug", L"Sep", L"Oct", L"Nov", L"Dec"
    }, {
        L"January", L"February", L"March", L"April", L"May", L"June",
        L"July", L"August", L"September", L"October", L"November",
        L"December"
    }, {
        L"Sun", L"Mon", L"Tue", L"Wed",
        L"Thu", L"Fri", L"Sat"
    }, {
        L"Sunday", L"Monday", L"Tuesday", L"Wednesday",
        L"Thursday", L"Friday", L"Saturday"
    },

    /* X_fmt */
    L"%H:%M:%S",

    /*
    ** x_fmt
    ** C99 requires this format.
    ** Using just numbers (as here) makes Quakers happier;
    ** it's also compatible with SVR4.
    */
    L"%m/%d/%y",

    /*
    ** c_fmt
    ** C99 requires this format.
    ** Previously this code used "%D %X", but we now conform to C99.
    ** Note that
    **  "%a %b %d %H:%M:%S %Y"
    ** is used by Solaris 2.3.
    */
    L"%a %b %e %T %Y",

    /* am */
    L"AM",

    /* pm */
    L"PM",

    /* date_fmt */
    L"%a %b %e %H:%M:%S %Z %Y"
};

#define UNKNOWN L"?"
static wchar_t *    _add(const wchar_t *, wchar_t *, const wchar_t *);
static wchar_t *    _sadd(const char *, wchar_t *, const wchar_t *);
static wchar_t *    _conv(int, const wchar_t *, wchar_t *, const wchar_t *);
static wchar_t *    _fmt(const wchar_t *, const struct tm *, wchar_t *, const wchar_t *,
            int *);
static wchar_t *    _yconv(int, int, int, int, wchar_t *, const wchar_t *);

extern char *   tzname[];

#define IN_NONE 0
#define IN_SOME 1
#define IN_THIS 2
#define IN_ALL  3

size_t
wcsftime(wchar_t *__restrict s, size_t maxsize,
    const wchar_t *__restrict format, const struct tm *__restrict t)
{
    wchar_t *p;
    int warn;

    tzset();
    warn = IN_NONE;
    p = _fmt(((format == NULL) ? L"%c" : format), t, s, s + maxsize, &warn);
    if (p == s + maxsize) {
        if (maxsize > 0)
            s[maxsize - 1] = '\0';
        return 0;
    }
    *p = L'\0';
    return p - s;
}

static wchar_t *
_fmt(const wchar_t *format, const struct tm *t, wchar_t *pt,
    const wchar_t *ptlim, int *warnp)
{
    for ( ; *format; ++format) {
        if (*format != L'%') {
            if (pt == ptlim)
                break;
            *pt++ = *format;
            continue;
        }
label:
        switch (*++format) {
        case '\0':
            --format;
            break;
        case 'A':
            pt = _add((t->tm_wday < 0 ||
                t->tm_wday >= DAYSPERWEEK) ?
                UNKNOWN : Locale->weekday[t->tm_wday],
                pt, ptlim);
            continue;
        case 'a':
            pt = _add((t->tm_wday < 0 ||
                t->tm_wday >= DAYSPERWEEK) ?
                UNKNOWN : Locale->wday[t->tm_wday],
                pt, ptlim);
            continue;
        case 'B':
            pt = _add((t->tm_mon < 0 ||
                t->tm_mon >= MONSPERYEAR) ?
                UNKNOWN : Locale->month[t->tm_mon],
                pt, ptlim);
            continue;
        case 'b':
        case 'h':
            pt = _add((t->tm_mon < 0 ||
                t->tm_mon >= MONSPERYEAR) ?
                UNKNOWN : Locale->mon[t->tm_mon],
                pt, ptlim);
            continue;
        case 'C':
            /*
            ** %C used to do a...
            **  _fmt("%a %b %e %X %Y", t);
            ** ...whereas now POSIX 1003.2 calls for
            ** something completely different.
            ** (ado, 1993-05-24)
            */
            pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
                pt, ptlim);
            continue;
        case 'c':
            {
            int warn2 = IN_SOME;

            pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
            if (warn2 == IN_ALL)
                warn2 = IN_THIS;
            if (warn2 > *warnp)
                *warnp = warn2;
            }
            continue;
        case 'D':
            pt = _fmt(L"%m/%d/%y", t, pt, ptlim, warnp);
            continue;
        case 'd':
            pt = _conv(t->tm_mday, L"%02d", pt, ptlim);
            continue;
        case 'E':
        case 'O':
            /*
            ** C99 locale modifiers.
            ** The sequences
            **  %Ec %EC %Ex %EX %Ey %EY
            **  %Od %oe %OH %OI %Om %OM
            **  %OS %Ou %OU %OV %Ow %OW %Oy
            ** are supposed to provide alternate
            ** representations.
            */
            goto label;
        case 'e':
            pt = _conv(t->tm_mday, L"%2d", pt, ptlim);
            continue;
        case 'F':
            pt = _fmt(L"%Y-%m-%d", t, pt, ptlim, warnp);
            continue;
        case 'H':
            pt = _conv(t->tm_hour, L"%02d", pt, ptlim);
            continue;
        case 'I':
            pt = _conv((t->tm_hour % 12) ?
                (t->tm_hour % 12) : 12,
                L"%02d", pt, ptlim);
            continue;
        case 'j':
            pt = _conv(t->tm_yday + 1, L"%03d", pt, ptlim);
            continue;
        case 'k':
            /*
            ** This used to be...
            **  _conv(t->tm_hour % 12 ?
            **      t->tm_hour % 12 : 12, 2, ' ');
            ** ...and has been changed to the below to
            ** match SunOS 4.1.1 and Arnold Robbins'
            ** strftime version 3.0. That is, "%k" and
            ** "%l" have been swapped.
            ** (ado, 1993-05-24)
            */
            pt = _conv(t->tm_hour, L"%2d", pt, ptlim);
            continue;
        case 'l':
            /*
            ** This used to be...
            **  _conv(t->tm_hour, 2, ' ');
            ** ...and has been changed to the below to
            ** match SunOS 4.1.1 and Arnold Robbin's
            ** strftime version 3.0. That is, "%k" and
            ** "%l" have been swapped.
            ** (ado, 1993-05-24)
            */
            pt = _conv((t->tm_hour % 12) ?
                (t->tm_hour % 12) : 12,
                L"%2d", pt, ptlim);
            continue;
        case 'M':
            pt = _conv(t->tm_min, L"%02d", pt, ptlim);
            continue;
        case 'm':
            pt = _conv(t->tm_mon + 1, L"%02d", pt, ptlim);
            continue;
        case 'n':
            pt = _add(L"\n", pt, ptlim);
            continue;
        case 'p':
            pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
                Locale->pm :
                Locale->am,
                pt, ptlim);
            continue;
        case 'R':
            pt = _fmt(L"%H:%M", t, pt, ptlim, warnp);
            continue;
        case 'r':
            pt = _fmt(L"%I:%M:%S %p", t, pt, ptlim, warnp);
            continue;
        case 'S':
            pt = _conv(t->tm_sec, L"%02d", pt, ptlim);
            continue;
        case 's':
            {
                wchar_t     buf[INT_STRLEN_MAXIMUM(time_t) + 1] ={0}; /*lint !e506*/
#ifdef LOSCFG_KERNEL_CPPSUPPORT
                struct tm   tm_s;
                time_t      mkt;

                tm_s = *t;
                mkt = mktime(&tm_s);
#endif
                if (TYPE_SIGNED(time_t) == true) /*lint !e506*/
#ifdef LOSCFG_KERNEL_CPPSUPPORT
                    (void)swprintf(buf,
                        sizeof buf/sizeof buf[0],
                        L"%ld", (long) mkt);
                else
                    (void)swprintf(buf,
                        sizeof buf/sizeof buf[0],
                        L"%lu", (unsigned long) mkt);
#endif
                pt = _add(buf, pt, ptlim);
            }
            continue;
        case 'T':
            pt = _fmt(L"%H:%M:%S", t, pt, ptlim, warnp);
            continue;
        case 't':
            pt = _add(L"\t", pt, ptlim);
            continue;
        case 'U':
            pt = _conv((t->tm_yday + DAYSPERWEEK -
                t->tm_wday) / DAYSPERWEEK,
                L"%02d", pt, ptlim);
            continue;
        case 'u':
            /*
            ** From Arnold Robbins' strftime version 3.0:
            ** "ISO 8601: Weekday as a decimal number
            ** [1 (Monday) - 7]"
            ** (ado, 1993-05-24)
            */
            pt = _conv((t->tm_wday == 0) ?
                DAYSPERWEEK : t->tm_wday,
                L"%d", pt, ptlim);
            continue;
        case 'V':   /* ISO 8601 week number */
        case 'G':   /* ISO 8601 year (four digits) */
        case 'g':   /* ISO 8601 year (two digits) */
/*
** From Arnold Robbins' strftime version 3.0: "the week number of the
** year (the first Monday as the first day of week 1) as a decimal number
** (01-53)."
** (ado, 1993-05-24)
**
** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
** "Week 01 of a year is per definition the first week which has the
** Thursday in this year, which is equivalent to the week which contains
** the fourth day of January. In other words, the first week of a new year
** is the week which has the majority of its days in the new year. Week 01
** might also contain days from the previous year and the week before week
** 01 of a year is the last week (52 or 53) of the previous year even if
** it contains days from the new year. A week starts with Monday (day 1)
** and ends with Sunday (day 7). For example, the first week of the year
** 1997 lasts from 1996-12-30 to 1997-01-05..."
** (ado, 1996-01-02)
*/
            {
            int year;
            int base;
            int yday;
            int wday;
            int w;

            year = t->tm_year;
            base = TM_YEAR_BASE;
            yday = t->tm_yday;
            wday = t->tm_wday;
            for ( ; ; ) {
                int len;
                int bot;
                int top;

                len = isleap_sum(year, base) ?
                    DAYSPERLYEAR :
                    DAYSPERNYEAR;
                /*
                ** What yday (-3 ... 3) does the ISO year
                ** begin on?
                */
                bot = ((yday + 11 - wday) % DAYSPERWEEK) - 3;
                /*
                ** What yday does the NEXT ISO year begin on?
                */
                top = bot - (len % DAYSPERWEEK);
                if (top < -3)
                    top += DAYSPERWEEK;
                top += len;
                if (yday >= top) {
                    ++base;
                    w = 1;
                    break;
                }
                if (yday >= bot) {
                    w = 1 + ((yday - bot) / DAYSPERWEEK);
                    break;
                }
                --base;
                yday += isleap_sum(year, base) ?
                    DAYSPERLYEAR :
                    DAYSPERNYEAR;
            }
            if ((w == 52 && t->tm_mon == TM_JANUARY) ||
                (w == 1 && t->tm_mon == TM_DECEMBER))
                    w = 53;
            if (*format == 'V')
                pt = _conv(w, L"%02d", pt, ptlim);
            else if (*format == 'g') {
                *warnp = IN_ALL;
                pt = _yconv(year, base, 0, 1, pt, ptlim);
            } else
                pt = _yconv(year, base, 1, 1, pt, ptlim);
            }
            continue;
        case 'v':
            /*
            ** From Arnold Robbins' strftime version 3.0:
            ** "date as dd-bbb-YYYY"
            ** (ado, 1993-05-24)
            */
            pt = _fmt(L"%e-%b-%Y", t, pt, ptlim, warnp);
            continue;
        case 'W':
            pt = _conv((t->tm_yday + DAYSPERWEEK -
                (t->tm_wday ?
                (t->tm_wday - 1) :
                (DAYSPERWEEK - 1))) / DAYSPERWEEK,
                L"%02d", pt, ptlim);
            continue;
        case 'w':
            pt = _conv(t->tm_wday, L"%d", pt, ptlim);
            continue;
        case 'X':
            pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
            continue;
        case 'x':
            {
            int warn2 = IN_SOME;

            pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
            if (warn2 == IN_ALL)
                warn2 = IN_THIS;
            if (warn2 > *warnp)
                *warnp = warn2;
            }
            continue;
        case 'y':
            *warnp = IN_ALL;
            pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, pt, ptlim);
            continue;
        case 'Y':
            pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, pt, ptlim);
            continue;
        case 'Z':
            if (t->tm_zone != NULL)
                pt = _sadd(t->TM_ZONE, pt, ptlim);
            else
                if (t->tm_isdst >= 0)
                    pt = _sadd(tzname[t->tm_isdst != 0 ? 1 : 0],  pt, ptlim);
            /*
            ** C99 says that %Z must be replaced by the
            ** empty string if the time zone is not
            ** determinable.
            */
            continue;
        case 'z':
            {
            int     diff;
            wchar_t const * sign;

            if (t->tm_isdst < 0)
                continue;
            diff = t->tm_gmtoff;
            if (diff < 0) {
                sign = L"-";
                diff = -diff;
            } else
                sign = L"+";
            pt = _add(sign, pt, ptlim);
            diff /= SECSPERMIN;
            diff = (diff / MINSPERHOUR) * 100 +
                (diff % MINSPERHOUR);
            pt = _conv(diff, L"%04d", pt, ptlim);
            }
            continue;
        case '+':
            pt = _fmt(Locale->date_fmt, t, pt, ptlim, warnp);
            continue;
        case '%':
        /*
        ** X311J/88-090 (4.12.3.5): if conversion wchar_t is
        ** undefined, behavior is undefined. Print out the
        ** character itself as printf(3) also does.
        */
        default:
            if (pt != ptlim)
                *pt++ = *format;
            break;
        }
    }
    return pt;
}

static wchar_t *
_conv(int n, const wchar_t *format, wchar_t *pt, const wchar_t *ptlim)
{
    wchar_t buf[INT_STRLEN_MAXIMUM(int) + 1]; /*lint !e506*/

    (void) swprintf(buf, sizeof buf/sizeof buf[0], format, n);
    return _add(buf, pt, ptlim);
}

static wchar_t *
_add(const wchar_t *str, wchar_t *pt, const wchar_t *ptlim)
{
    while (pt < ptlim && (*pt = *str++) != L'\0')
        ++pt;
    return pt;
}

static wchar_t *
_sadd(const char *str, wchar_t *pt, const wchar_t *ptlim)
{
    while (pt < ptlim && (*pt = btowc(*str++)) != L'\0')
        ++pt;
    return pt;
}
/*
** POSIX and the C Standard are unclear or inconsistent about
** what %C and %y do if the year is negative or exceeds 9999.
** Use the convention that %C concatenated with %y yields the
** same output as %Y, and that %Y contains at least 4 bytes,
** with more only if necessary.
*/

static wchar_t *
_yconv(int a, int b, int convert_top, int convert_yy, wchar_t *pt,
    const wchar_t *ptlim)
{
    register int    lead;
    register int    trail;

#define DIVISOR 100
    trail = a % DIVISOR + b % DIVISOR;
    lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
    trail %= DIVISOR;
    if (trail < 0 && lead > 0) {
        trail += DIVISOR;
        --lead;
    } else if (lead < 0 && trail > 0) {
        trail -= DIVISOR;
        ++lead;
    }
    if (convert_top) {
        if (lead == 0 && trail < 0)
            pt = _add(L"-0", pt, ptlim);
        else    pt = _conv(lead, L"%02d", pt, ptlim);
    }
    if (convert_yy)
        pt = _conv(((trail < 0) ? -trail : trail), L"%02d", pt, ptlim);
    return pt;
}

